This morning’s Daily Telegraph carries the story of a confrontation between Jeremy Hunt, the Health Secretary, and Dr Sarah Wollaston MP, the Tory Chair of the Health Select Committee.

Wollaston, who was a GP before being selected to stand for Parliament, accuses Hunt of suppressing a report by Public Health England (PHE) into the efficacy of a sugar tax.

Both Hunt and David Cameron are opposed to a tax, and the MP for Totnes is “suspicious” that the Government is suppressing the report because it comes out in favour, and will thus increase pressure on them.

The Health Secretary, naturally, denies this. He maintains that the report is part of the Department’s policy formulation process and will be published later.

Without a window into Hunt’s soul the truth is impossible to know for sure. But Wollaston’s accusation is at least plausible, and this is a troubling development – but not, perhaps, for the reasons she thinks.

To explain why, I draw attention to two points in the Telegraph article.

First, when setting out her case for the immediate publication of the PHE report, Wollaston writes stirringly: “Why should campaigners be denied access to an important evidence base paid for by the public purse for the benefit of the nation’s children?”

Note the supposed beneficiary of the decision to publish: “campaigners”. Elsewhere she refers to “the wider public health community”.

Second, the paper also writes: “She said the public health body had a duty to publish the evidence “regardless of how inconvenient it might be” in order to allow an informed public debate.”

This is an admirable sentiment, but not one that the aforementioned “public health community” is reliably enthusiastic about, if their determined efforts to completely shut tobacco companies out of the debate is anything to go by.

Of course, a study conducted by an organisation with a vested interest should be scrutinised carefully.

But the wholesale exclusion of commercial interests – who are the only party other than the “public health community” with an interest in funding the relevant research – is surely deeply inimical to “an informed public debate”, as is the de facto exclusion of “inconvenient” research from liberty-centred organisations like the Institute for Economic Affairs.

A debate, after all, needs two sides.

Public policy campaigners – even when they are doctors and scientists – are partisans (often well-paid partisans), not dispensaries of objective truth.

Similarly, for all its technocratic pretensions “public health” is in fact an ideological stance, which hinges on the too-little-examined assumption that the state has both the right and the duty to force citizens to forgo pleasure to extend life.

(How this squares with the fact that our overstretched welfare systems look set to collapse beneath the unsustainable weight of an ageing population is beyond me; the two debates seem to occur in parallel universes to each other.)

Thus in the debate curated by the Health Committee and the “public health community”, the underlying assumptions of the authoritarian response are pre-agreed. The debate is about “what works”, hence the decisive power of evidence.

In a proper, pluralistic political debate, evidence is not quite so all-conquering. ‘Evidence’ is just data, and data prescribes nothing. It is perfectly possible for two people with different principles to respond to the same evidence in very different ways without either being mendacious or stupid.

If the Prime Minister and his Health Secretary oppose a sugar tax on grounds other than efficacy – it would be extraordinarily regressive, not to mention an enormous intrusion on individual choice – then they should have no trouble standing by those arguments, even if they were certain that pricing sugar out of the diets of the poor was practicable.

But that would involve saying: “This would lengthen – sorry, save – people’s lives, but is still wrong. There are more important things than longevity.” And when did we last hear a politician of the first rank advance such a thesis?

OK, Boris Johnson did when he rejected a proposal to ban smoking in parks. But he’s Boris, and such flashes of humanising heresy are part of what make him so unique.

This Government, with its support for plain packaging, has firmly conceded the underlying assumptions of authoritarian public health policy.

So we can see why Hunt might, theoretically, be worried about the political pressure which would result from being trapped between a public health establishment armed with evidence that a tax would ‘work’ and a sugar-loving, vote-wielding public.